1. Field of the Invention
The present invention relates to an orthopedic medical apparatus and, more particularly, to a femur supporting device to be mounted in a femur for cooperating with an acetabular cup to form an artificial hip joint.
2. Description of the Related Art
FIG. 1 shows a conventional femur supporting device 9 including a seat 91, a stem 92, and an inclined post 93. The stem 92 includes a handle end 921 and a joint end 922. An end of the inclined post 93 is integrally connected to the joint end 922 of the stem 92. In assembly, the handle end 921 of the stem 92 extends through the seat 91, and the seat 91 is engaged at a location adjacent to the joint end 922 to securely position the stem 92.
When it is desired to implant the conventional femur supporting device 9 into a human body, the muscle and ligament enveloping a femur F are cut open first, and the femoral neck and the femoral head are removed by cutting. Then, the cancellous bone of the femur F is drilled to form a hole for implantation of the conventional femur supporting device 9. After implantation of the conventional femur supporting device 9 into the femur F, the inclined post 93 extends obliquely beyond the femur F of the patient to replace the femoral neck. An acetabular unit (not shown) can be coupled to a free end of the inclined post 93.
However, the conventional femur supporting device 9 withstands the vertical stress of the body and the oblique torque of the femoral trochanter by a single inclined post 93, which is difficult to effectively disperse the load. Thus, the conventional femur supporting device 9 is apt to malfunction after a period of time.
Furthermore, the inclined post 93 is integrally connected to the stem 92, such that it is impossible to change the length of the stem 92 or the inclined post 93 according to the shape of the bone of the patient and impossible to adjust the inclination angle between the inclined post 93 and the stem 92. Thus, it is necessary to manufacture conventional femur supporting devices 9 of many specifications for selective use, which is very inconvenient to material management for hospitals and causes inventory pressure to the manufacturers. Furthermore, the conventional femur supporting device 9 of each specification contains the whole stem 92 and the whole inclined post 93, which consumes a large quantity of material, results in high costs, and requires considerable space for inventory.
An example of the above conventional femur supporting device 9 has been disclosed in Taiwan Patent No. I312677 entitled “Artificial Femoral Structure”. Taiwan Utility Model No. M394805 entitled “Femoral Prothesis”, Taiwan Utility Model No. M389530 entitled “Antibiotic-Containing Bone Cement Femoral Supporting Device with High Resistance to Pressure”, and Taiwan Patent No. I305722 entitled “Artificial Bone with Porous Tissue” disclose similar structures and, thus, have the same disadvantages.
Thus, improvement to conventional femur supporting devices is necessary.